A conventional way to rotate a bolt or a screw with a head is to use a wrench or a socket, the wrench has an open clamping space so that the hexagonal head of the bolt of screw is clamped by two jaws of the wrench. At least two sides of the hexagonal head can be clamped by the jaws and when the wrench is rotated, the bolt or screw is rotated. A similar way for the socket or a box-end wrench to rotate the bolt or screw. Another type of bolt or screw has a round head with hexagonal recess defined in the head, a hexagonal driving tool is needed to rotate this type of bolt or screw. The hexagonal driving tool is sized such that it can be inserted and engaged with the hexagonal recess in the head of the bolt or screw, such that the bolt or screw can be rotated when rotating the hexagonal driving tool. Nevertheless, if the hexagonal recess is rounded, it is difficult to use the hexagonal driving tool to rotate the bolt or screw.
The present invention intends to provide a hexagonal driving tool which includes a hexagonal driving rod which has a groove for receiving a pawl piece therein, one side of the pawl piece is pushed by a spring out from the driving rod so as to be engaged with the rounded corner of the hexagonal recess such that the bolt or screw with the rounded hexagonal recess can be rotated.